Tropically stable novel oral lipid formulation of amphotericin B (iCo-010): biodistribution and toxicity in a mouse model

BACKGROUND: The purpose of this study was to evaluate the biodistribution and toxicity of amphotericin B (AmB) following multiple oral administrations of a novel tropically stable lipid-based formulation (iCo-010). METHODS: BALB/c mice were allocated into six groups: oral iCo-010 twice daily for 5 days in the dose of 20, 10, 5 and 2.5 mg/kg; vehicle control; and intravenous boluses of Fungizone(® )2 mg/kg once daily for 5 days. The animals were sacrificed 12 h following the last administration and blood and tissues were collected. RESULTS: The plasma concentrations of AmB were similar to previously reported after administration of iCo-009. Somewhat lower concentrations of AmB were detected in reticulo-endothelial system in the case of iCo-010 when compared with iCo-009. The concentration in kidney was higher with iCo-010 than with iCo-009. The creatinine levels in all oral treatment groups were in a normal range as in the case of iCo-009. Administration of Fungizone(® )resulted in elevated plasma creatinine levels. Histopathology analysis detected no GI, liver or kidney toxicity following multiple dose oral administration of iCo-010. Fungizone(® )treatment induced necrotic changes in hepatic and kidney tissues. CONCLUSIONS: Given the tropical stability of iCo-010, near identical activity against visceral leishmaniasis and significant concentrations in target organs this formulation has a potential to become a treatment of choice in tropical developing countries.